Nacla
07-07-2014, 18:48
(This is the first time I've ever posted anything online anywhere. I've been a lurker at TDP off-and-on for several years now.)
Background information: A mechanic friend offered to help me track down a problem in my '93 6.5L TD engine, suspecting that a blown head gasket might be the cause of the excess white/blue smoke I'm seeing for a few minutes upon initial engine start-up. Another symptom is bubbling in the plastic coolant reservoir, which continues for a short while after the engine is shutdown when warm. Also, the original radiator now has a hole in it, and will have to be repaired or replaced, when the above repairs take place next month.
What I'm thinking about having installed: Another friend is leaving Alaska, and has gifted me with a spare set of plastic-bag-enclosed rebuilt "567" heads (46mm intake & 39mm exhaust valves) that he'd had a local machine shop redo for his own truck. The heads were checked for defects and are reported to be straight and crack-free. (My uneducated eye cannot spot any cracking between the valves.)
My concerns: The rebuilt "567" heads are presently equipped with crack-free 2-dot precups ("J"-code precups?) which IIRC were only used in certain HD applications in NA 6.2L engines. Do these need to be swapped out with my stock precups? (I'm assuming the "T" style turbo precups are what were installed in the existing heads.)
I think I've read one of More Power's (Jim's) early posts where he indicated the tiny little (unmarked) 6.2L "C"-code precups might work in a 6.5L TD, if maximum MPG is the goal. The 2-dot precups have larger openings than the "C"-code precups. If the 2-dot precups are used, am I going to lose lots of power? Should a swap be left to a machine shop, or is this more of a DIY-project?
Vehicle use: Mostly this truck will be used as a DD. I do tow a 3600 lb riverboat/trailer once a year, and the trip entails pulling up some hills.
If I've overlooked some prior post concerning 2-dot precups and 6.5L TD engines, I'd appreciate it if someone would point me in the right direction. Thanks for taking the time to respond. - Nacla
Background information: A mechanic friend offered to help me track down a problem in my '93 6.5L TD engine, suspecting that a blown head gasket might be the cause of the excess white/blue smoke I'm seeing for a few minutes upon initial engine start-up. Another symptom is bubbling in the plastic coolant reservoir, which continues for a short while after the engine is shutdown when warm. Also, the original radiator now has a hole in it, and will have to be repaired or replaced, when the above repairs take place next month.
What I'm thinking about having installed: Another friend is leaving Alaska, and has gifted me with a spare set of plastic-bag-enclosed rebuilt "567" heads (46mm intake & 39mm exhaust valves) that he'd had a local machine shop redo for his own truck. The heads were checked for defects and are reported to be straight and crack-free. (My uneducated eye cannot spot any cracking between the valves.)
My concerns: The rebuilt "567" heads are presently equipped with crack-free 2-dot precups ("J"-code precups?) which IIRC were only used in certain HD applications in NA 6.2L engines. Do these need to be swapped out with my stock precups? (I'm assuming the "T" style turbo precups are what were installed in the existing heads.)
I think I've read one of More Power's (Jim's) early posts where he indicated the tiny little (unmarked) 6.2L "C"-code precups might work in a 6.5L TD, if maximum MPG is the goal. The 2-dot precups have larger openings than the "C"-code precups. If the 2-dot precups are used, am I going to lose lots of power? Should a swap be left to a machine shop, or is this more of a DIY-project?
Vehicle use: Mostly this truck will be used as a DD. I do tow a 3600 lb riverboat/trailer once a year, and the trip entails pulling up some hills.
If I've overlooked some prior post concerning 2-dot precups and 6.5L TD engines, I'd appreciate it if someone would point me in the right direction. Thanks for taking the time to respond. - Nacla